Rock-drilling machine.



Patented Aug. 22, I899.

W. GLEESDN.

ROCK DRILLING MACHINE.

(Application filed Nov. 9, 1898.)

(No Model.)

e; i x I. "n

UNITED STATES- PATENT OFFICE.

\VILLIAM GLEESON, OF UN GA, ALASKA TERRITORY.

ROCK-DRILLING MACHINE.

SPECIFICATION forming part of Letters Patent No. 631,712, dated August22, 1899.

Application filed November 9,1893. Serial No. 695,951. (Nomodel-l To allwhom, it may concern.-

Be it known that I, WILLIAM GLEESON, a citizen of the United States,residing at Unga, in the Territory of Alaska, have invented cer tain newand useful Improvements in Rock- Drilling Machines; and I hereby declarethe following to be a full, clear,'and exact description of the same,reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates to an improvement in percussive rock-drillingmachines commonly operated by compressed air and to a means ofregulating and controlling the strokes of the same.

My improvements consist in providing an auxiliary piston so arranged asto act upon the distributing-valve in addition 'to the regular or usualmeans of actuating the same, so

the valve can be reversed on the back stroke of the piston and causeshort strokes thereof, as circumstances may demand.

The objects of my invention are to enable short strokes to be made atstarting the drill,

in withdrawing itwhen choked or jammed in holes, or in any case wheresuch short strokes are required.

To these ends I construct rock-drilling machines as shown in thedrawings herewith and forming a part of this specification, in 1 which-'Figure I is a longitudinal section through a rock-drilling machineprovided with my im-v provement. Fig. II is a broken end view of Fig. I,partially in section. Fig. III is a partial plan of Fig. I, a portionbeing shown in section. Fig. IV is a partial side elevation of the samemachine, obverse to Fig. I. Fig.V is adetail showmg the lever to operatethe cock that-controls the stroke of the main piston.

Referring to the drawings and the numerals of reference thereon, 1 isthe main cylinder; 2, the main piston, divided into two parts 3 and at.The valve-box 5, slide-valve 6, induction 7 8, exhaust-way 9, anddrill-stem 10 are all of the usual construction and do not requiredescription.

The slide-valve 6 is moved by the oscillating tappet 11, pivoted at 12and moved each way by the faces 13 14,which come in contact with thetappet 11, impinging at 15 and 16, moving this tappet 11 and theslide-valve 6 right and left, as indicated in Fig. I. The removableintermediate plate 17 is to permit convenient repairing of thevalve-seat.

Steam enters the valve-box 5through an inlet-Way at 18 from either sideand passes under the ends of the valve 6 to the'ports 7 and '8 and intothe chambers 19 and 20 as the valve 6 is moved to the right or left,thus producing a reciprocating mot-ion of the piston 2 and of thedrill-stem 10. The central or exhaust port 9 communicates with theannulus 21 around the main piston 2, and the air or steam escapestherefrom by nozzle to the open air.

Thus far the parts are in construction and operation similar torock-drilling machines as commonly made, the slide-valve and pistonmoving throughout a full range or stroke. Myimprovement now to bedescribed modifies this range, causing'the piston to make short strokesat beginning to drill a hole, in working the drills out when choked, orin any other case when such short movement is desirable.

To carry out my invention in a simple manner, I provide at the rear endof the valvebox 5, either integral therewith or attached thereto, asmall cylinder 22, with a piston 23 to slide therein. This piston 23 isprovided with a stem 24, that passes into the valvebox 5, adaptedto'bear against the end of the slide-valve 6, as seen in Fig. I. Thispiston is moved forward or toward the valve 6 by means of the compressedair in the valve-box 5, which passes through a small port 25 (seen inFig. III) and fills the outer end of the cylinder 22, pressing thepiston 23 and the stem 24 inward or toward the valve 6 with a forceequal to the pressure of the fluid and the size of the piston, theproportion of the latter be ing approximately as shown in Fig. I. Thisproduces an action as follows: Supposing the various parts to be in theposition seen in Fig. I, the slide-valve 5 admitting air to the chamber19 and the main piston 2 and the stem 10 to be moving forward, if thepiston 23 is not acting the main piston would move on until the curvedface at 13 came in contact at 15 with the tappet 11. This would completethe forward stroke; but if the piston 23 is pressing the stem 24 againstthe valve 6 as soon as the beveled face 14 on the piston-head at passesfrom beneath the beveled face 16 of the tappet 11 the piston 23 willadmitting air or steam to the passage 8 and vIO theforward side.

instantly reverse the slide-valve 6, moving it, and the tappet 11 to theopposite position,

the chamber 20, thus reversing the motion of the piston 2 and producinga short stroke. The length of such stroke, as will be seen, depends uponthe length and inclination of the face 16 on the tappet 11 and can bearranged accordingly. The proportions shown give a good result inWorking. As, however,- such short strokes are required only undercertain circumstances I provide for the normal operation of the machineby arresting and reversing the motion of the piston 23 in the followingmanner: When the piston 23 is in action and the main piston 2 is makingshort strokes, the-chamber 26 in the front of this piston is incommunication with the external air by means of a passage 27 (indicatedin Figs. II and III) and is thus relieved of pressure on When the pistonis to cease,

- acting, this passage 27 is closed by a cock 28,

operated by a lever 29. As soon as this cook 28 is closed: air leakspast the piston 23 and fills the chamber 26, putting the piston 23 intoequilibrium, and the spring 31 presses the piston 23 back, holding thestem 24 clear of the valve 6, permitting the latter to move freely,producing full strokes of the main piston 2. In case the piston 23 isfitted so closely as to exclude the compressed air from the chamber 25or to require too long a time to produce a pressure in this chamber asmall hole or groove 32 can be formed in the piston 23 to permit theslowpassage of air, butin practice the amount that leaks past the piston23 is found to be suificient.

' The lever 29 ismade with a square head-33, against which bears aspring 34, as seen in Figs. III and IV, that serves to keep the handle29 in position when it is set to open or close the cock 28. In thismanner it will be seen that as soon as the cook 28- is opened the mainpiston 2 will begin and continue with short strokes until this cock isclosed.

The machine will then operate normally at full stroke, the onlyadjustment required be ing to turn the handle 29 one-fourth of arevolution to the right or left, as may be most convenient. It will beunderstood that a spring maybe substituted for the piston to press thestem 24 against the slide-valve 6 and produce short strokes of thepiston and drill in the same manner, but the devices here shown arebelieved to be the most simple and effective.

Having thus explained the nature and ob-v jects of my invention and amanner of applying the same, What I claim as new, and desire to secureby Letters Patent, is-

1. In a rock-drilling machine, in combination, a main cylinder, apiston, a distributing slide-valve, a tappet to move the said valve eachway by the'movements of the piston, a stem bearing against one end ofthe valve, and

" means for applying elastic pressure at will to said stem, wherebyshort or long strokes of the piston may be produced at will,substantially as specified.

2. In a rock-drilling machine, a cylinder, piston, and distributingslidewalve, a tappet to move said slide-valve, positively actuated bycontact with the reciprocating piston, and an auxiliary piston forapplying elastic pres= .snre to the slideevalve at one side thereofinpress upon and move the valve inadvance of the tappet action, toshorten the strokes of the piston and of a drill operated thereby,substantially as specified.

4. In a rock-drilling machine, a maincylinder, piston, anddistributing-valve therefor,

.a tappet to move said valve, a supplementary piston adapted to act uponand move thedistributing-valve, in one direction, in advance of thetappet for normally actuating the same, whereby the main piston anddrill stem will act with short strokes, substantiallyas specified.

5. In a rock-drilling'machine, a main cylinder, piston anddistributingwalve therefor, a tappet to move said valve,. a passage forair leading from the valve-box and air-supply 1 to the rear side of anauxiliary piston, causing this to press upon and move the distrilr,uting-valve to produce short strokes of the machine and the drillsoperated thereby, substantially asspecified.

6. In a rock-drilling-machine, a main cylinder and piston, and adistributing-valve therefor, a tappet to move said valve, an auxiliarycylinder and piston to move the distribnting-valve in advanceof thetappet action, a passage from theinner end of the aux- I iliary cylinderand inner sidev of the auxiliary piston to the openv air and a cock toopenand close this passage, substantially as, and for the purposesspecified.

These features I believe to benovel and useful, and ask that LettersPatent be granted therefor. I

YVILLIAM GLEESON. Witnesses:

JOHN DELZELL, JOSEPH H. BAKER.

